<<Gah. WD 40 being a petroleum product isn't what I would use near
rubber/neoprene. Plain old dish washing detergent will do the trick fine
won't harm the rubber and washes off and away without any problem.>>

Yep.
Most all the glazer's in this area been using WD-40 for as long as it's
been available.

Soap is good if that's all ya got.
It dries too fast and will drag the tool down to a slow yank instead of
a smooth slide operation.